Dual Batteries

Quote:

Originally Posted by JamesH

My system is similar to KhunMoo's but it has a simple two way switch A, A+B. Running the car on B only is not a problem (both A & B are normal cranking batteries). The thing that leaves me uneasy about it is that EVERYTHING is connected to the main cranking battery even the 12v plug in the back. I'd like to at least have the rear plug attached to battery B. When I had the car at an auto-electrician getting a new clamp for the batteries and a new switch that wore out I asked them to re-wire the back plug to battery B but he talked me out of it. He said the system I have is nice and simple and apart from the switch wearing out is bullet-proof. If you are disciplined about isolating the B battery when pulling up to camp, you always know where you stand with it. You have one fully charged battery sitting there ready to start your car in the morning.

Anyway for 99% of the time the switch is set to A+B so both batteries crank the car, it's only when I have the fridge in the back I ever isolate.

I fear flat batteries in the bush more than I fear crocs and king browns...

Just my 2 cents worth James, I have the same system and only have either bat A or bat B selected at any one time. The beauty of the system is its simplicity and having A+B connected would in my opinion be asking for trouble. I would only use it like this if jump starting a vehicle with flat battery. BTW all accessories run off the battery that is selected which gives you a good battery always for starting.